While Iowa Governor Tom Vilsack isn’t publicly promoting himself as a potential Vice Presidential runningmate for Massachusetts Senator John Kerry — another prominent state democrat is. Iowa Senator Tom Harkin says Kerry needs to select a governor as a runningmate to give the ticket balance. Harkin brought the issue up during a conference call today with reporters.He says no sitting Senator has ever defeated a president, and he says for balance he can’t see anyone better than Vilsack. Harkin says Vilsack would bring a lot to the Democrat campaign, he says Vilsack has a great life story and has experience as a mayor and legislator. He says Iowa and the states around it are swing states, and will be very important in the election.Vilsack has said he won’t run for another term as governor when this term expires.